C / C++ / MFC

1-Apr-06 15:47

hey, working with winpcap and trying to create a dll, my source is working, except the compiler will not build my project because it is complaining about unreferenced identifiers, which are referenced in the wpcap.lib file. I added the lib to my files using project > add to project > files.. and that didn't work. I then tried adding the reference via ALt + F7 > link tab and that didn't work either. I am rather new to visual studio and am at a loss. What do I need to do to link the library to my project? thanks in advance.

nada

Saurabh.Garg1-Apr-06 16:15

Saurabh.Garg

1-Apr-06 16:15

You do not add lib files to project, instead you have to add them to
project -> settings -> link tab. There should be something called additional libs. I don't remember what exactly it is called and I dont have vc 6.0.

-Saurabh

borono1-Apr-06 16:51

1-Apr-06 16:51

OK, I tried:

1. Project
2. Settings
3. Link Tab
4. Switched 'Category' to 'Input'
5. A Text field appeared with the name, 'Additional Library Path'
6. I typed the path: c:\mylibs
7. OK

Doesn't work. Repeat steps 1 - 6, but included the name of the lib with path. Clicked OK, and still not working.

Does it matter that I am writing a dll, because the lib works in the exe I wrote but not in the dll project. I didn't create the initial exe project, so I don't know how it was linked, I simply built off the example.

Anymore help, anyone? thanks in advance.

Michael Dunn1-Apr-06 17:36

Michael Dunn

1-Apr-06 17:36

You still need to put the lib filename itself in the list of libs, so the linker looks in it for symbols.

--Mike--
Visual C++ MVP Cool | :cool:

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borono1-Apr-06 18:01

1-Apr-06 18:01

I've just recently tried that as well, however, that did not work either. I ahve no idea why not. I figure if I specfied the directory the lib is in and include it in the list, I should be able to use it in my project --that is not the case.

I absolutley NEED this lib to link up, otherwise my code is completly functionless. What else should I be doing? I looked at my exe project: the one that the lib is currently linked and working --I saw no reference to the lib in links. Instead, the lib was listed amongst the source, def, header, etc.. files. I have no idea how it was linked.

I am currently learning how to write dlls, and it would be a great help to get this working, so thank you thus far, any more ideas, and thanks in advance.

ThatsAlok1-Apr-06 18:07

ThatsAlok

1-Apr-06 18:07

try #pragma comment(lib,_T("yourlibaray name"))

borono1-Apr-06 18:25

1-Apr-06 18:25

I put that in stdafx.h, right? Well, I tried it there and it said:

[quote]
Line (13) : warning C4083: expected 'string'; found identifier '_T'
[/quote]

...then I tried it in the main source file and it said the same. I have seen that suggested in other forums, do I need to put the path as well or just the name? Do I still need to add the references to the lib in the link tab or no? BTW, since I have read to use the pragma thing, I have tried it this way:

[quote]
#pragma comment( lib, "wpcap.lib")
[/quote]

...and that did not work as well. I thought the added _T() thing would be the solution. thanks anyway.. any more ideas from anyone? thanks

Waldermort1-Apr-06 18:32

1-Apr-06 18:32

borono wrote:
#pragma comment( lib, "wpcap.lib")

What is the exact error when you try using this? Can you copy and paste the output from the bottom of MSVC.

borono1-Apr-06 18:37

1-Apr-06 18:37

sure, here it is:

--------------------Configuration: test - Win32 Release--------------------
Compiling...
test.cpp
C:\test.cpp(24) : error C2065: 'pcap_findalldevs_ex' : undeclared identifier
C:\test.cpp(24) : error C2065: 'PCAP_SRC_IF_STRING' : undeclared identifier
Error executing cl.exe.

test.dll - 2 error(s), 0 warning(s)

thanks in advance

Waldermort1-Apr-06 18:41

1-Apr-06 18:41

This is not a lib error, this error means you are trying to use a function which the compiler cannot find. Did you include the header file for winpcap

#include <pcap.h>

-- modified at 0:42 Sunday 2nd April, 2006

borono1-Apr-06 18:59

1-Apr-06 18:59

yes. I added it to the project via project > add to project > files... then in code as you have above. I looked in the header and the pcap_findalldevs_ex identifier is not listed, only pcap_findalldevs is, and neither is PCAP_SRC_IF_STRING.. those are identified in the wpcap.lib file. That is why I assumed the lib was not linked properly. I have the associated .dll for the lib, so it should work if linked properly, I assume. I must have screwed something up in the transition. It has to be in the way I am linking the header or lib. Assuming the header is present, the lib is linked via the links tab, what else could be the problem and/or possible soultion? I appreciate the help guys. thanks

Waldermort1-Apr-06 19:06

1-Apr-06 19:06

borono wrote:
those are identified in the wpcap.lib file

A defined function is only a function name, these will be in your header files and they tell the compiler that there is a function of that type, the linker then tries to find it.

A declared function is a function and all of it's code, this would be in a source file, or in your case a lib file.

The problem you are having is that the compiler doesn't know that the function exists.

Add this line directly before you include pcap.h #define HAVE_REMOTE
and let me know.

-- modified at 1:09 Sunday 2nd April, 2006

Another note, you can't find them in the header file because you are looking in the wrong one. Take a look in the remote-ext.h header file

borono1-Apr-06 19:29

1-Apr-06 19:29

I dont know if I did the equivalent. I did this and it compiled with no errors, just a minute ago.

1. Project
2. Settings
3. C/C++ tab
4. Change Settings For to All Configurations
5. Preprocessor Defintions add: HAVE_REMOTE
6. OK

I now have to figure out why the dll when called is crashing the app. At least I can start working on the code again, that was rather annoying to deal with, indeed. I will try to do it your way to see if that makes a difference at run time. I appreciate the help a lot, I might come back once I get a handle on this dll and actually start coding something. I will most likely have questions. haha

Anyway, I guess this is solved. Thanks again

best regards

Waldermort1-Apr-06 19:34